Removing downhole barriers by dissolving them is a concept illustrated in U.S. Pat. Nos. 7,690,436; 7,661,481 and 7,703,511. Materials that dissolve or disintegrate in water are known such as aluminum alloys which are about 50% aluminum, 40% tin and 10% zinc are known and used for metal wire and sold by Praxair subsidiary TAFA Incorporated. This material is known to dissolve or disintegrate in water and is called 300/301—Dissolvable Metal Wire on the Material Safety Data Sheet provided by Praxair.
Producing a bell in a tubular was in the past accomplished with a variable swage that could form the bell at the bottom of a tubular being expanded and then be reconfigured to another size for further expansion of the balance of the tubular or for removal from the tubular. Adjustable swages are fairly complex devices so they always presented some risk of mechanical malfunction when switching dimension.
What is needed and provided by the present invention is a method to make a bell or recess in a tubular that can have a variety of purposes and accomplishing the formation of such a bell or recess with a swage that operates at preferably a single dimension. The method involves the use of a material that dissolves or disintegrates with exposure to a material such as water and yet has the strength to remain in position as a swage passes by the material so that the presence of the material is used to enhance the enlargement of the tubular where the material is disposed during the expansion. After the expansion the material is simply removed with an appropriate material such as water, for example, and there remains a zone of enlarged diameter which can be a bell at the bottom of a tubular or a recess if disposed at another location along the length of the tubular. Thereafter the presence of a bell can be used to secure another tubular into the bell and retain the internal dimension of the tubular above into the newly expanded tubular. If there is a recess produced in a given tubular the recess can be used as a locating groove for landing other tools at a predetermined location.
Other variations are envisioned such as protective sleeves such as for highly polished seal bores, no-goes for other tools and ball seats among other applications. The common theme to the various applications is the use of a simple swage and the ease of removal of the material after the swage moves through it. In the preferred embodiment the aluminum alloy made by TAFA is preferred as it is simply removed in the presence of water. Coatings on the material can also be employed that are then removed by the swage or through other means before or during the expansion. While a swage is recited to accomplish the expansion, various other devices can be used to expand a tubular shape such as extendable rollers from a housing or spaced seals that have pressure applied between them or other devices that can increase the dimension of one or more tubulars. Those skilled in the art will better understand the invention form a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is given by the appended claims.